(1) Field of the Invention
The present invention relates to a thermoplastic resin composition having a superior heat resistance, impact resistance and plating properties. More particularly, it relates to a thermoplastic polyphenylene ether resin composition having such properties.
(2) Description of the Related Art
The polyphenylene ether resin has a superior heat resistance, mechanical properties, and electrical properties, and good properties such as a low water absorption and high dimensional stability. Although this resin has a poor molding processability and impact resistance, these defects are overcome by blending a rubber-reinforced resin such as rubber-reinforced high-impact polystyrene, and such blends are currently widely used.
Almost all polyphenylene ether resin compositions used in the field of plating are formed by blending a polyphenylene ether resin with an ABS resin. Unlike high-impact polystyrene, the ABS resin (AS resin) has a poor compatibility with the polyphenylene ether resin, and therefore, lamellar peeling occurs in the blend.
As the means for overcoming this defect, Japanese Unexamined Patent Publication No. 53-154754 and Japanese Examined Patent Publication No. 63-7580 propose a method comprising blending an AS resin having a low acrylonitrile content with a polyphenylene ether resin, but even according to this proposal, a composition having not only satisfactory plating properties (such as throwing power and adhesion strength) but also impact resistance cannot be obtained.
It has been considered that, to plate a composition by the plating process for ABS resins a vinyl cyanide monomer should be present in the composition, but a copolymer of the vinyl cyanide monomer and an aromatic vinyl monomer or a graft copolymer obtained by grafting the vinyl cyanide monomer and an aromatic vinyl monomer to a rubbery polymer has a poor compatibility with the polyphenylene ether resin, and therefore, lamellar peeling occurs in the blend or the physical properties are lowered.